......Air Canada's flight 797 was
operating from Dallas, Texas to Toronto, Ontario on the afternoon of June 2,
1983. On the flight deck was Captain Donald Cameron and First Officer Claude
Ouimet. Three flight attendants

and 41 passengers were also on board the
DC-9 that day.
Cruising at FL330
over Lousiville, Kentucky, the pilots heard three snaps in sudden succession.
Looking behind Cameron's seat, Ouimet spotted three circuit breakers which
had popped out. "Which one is that?", Ouimet asked. "DC bus...the left
toilet...the left toilet flushing motor" Cameron replied. The Captain then
attempted to reset the breakers, but they would not stay in. Ouimet asked if
they should log it to which Cameron replied "I want to log it, yes. Somebody
must have pushed a rag down the toilet or something...jammed it and it's
over heated."

797 Burns on the Runway

Flt
797 was then handed off to Indianapolis
Center and
after a few minutes, Cameron tried again to reset the breakers, but to no
avail. In the back of the cabin, a passenger had drawn to the attention of a
flight attendant greyish smoke coming from under the door of the left
toilet. The flight attendant attempted to enter the toilet with a fire
extinguisher, but the thick smoke was too powerful. Another flight attendant
went forward to the flight deck and said to Cameron "Excuse me Captain,
there's a fire in the washroom at the back. They're just going back to put
it out." Cameron then instructed Ouimet to go back and take a look at the
situation. The third flight attendant had now opened the toilet door and
discharged the fire extinguisher. Passengers were now being moved forward
away from the smoke. Ouimet was unable to reach the toilet by this time
because the smoke had become too thick, but the flight attendant told him
that he had seen no flames in the washroom while discharging the
extinguisher. Ouimet went back to the flight deck to get a pair of goggles,
but the flight attendant came forward, saying the smoke had begun to
dissipate. Ouimet got goggles regardless and went back to the rear of the
aircraft. Just after he left, the master caution light illuminated on the
panel, indicating a loss of the left AC and DC power systems. In the back,
Ouimet found the toilet door hot to the touch and was about to tell the
other flight attendant not to open the

door when he saw the flight
attendant
at the front of the aircraft waving him hurriedly back to the flight deck.
As he reached the flight deck, he saw that now the emergency AC and DC buses
had lost power. The crew activated the emergency battery power and Ouimet
said "I don't like what's happening, I think we'd better go down." Cameron
then told the flight attendant s that they would be making an emergency
descent and to prepare the cabin. Ouimet made a mayday call to Indianapolis
as Cameron put the aircraft into it's descent. As the descent began, there
was a noise from the aft of the aircraft and black smoke began to billow
forward. Indianapolis instructed 797 to descend to 5000ft for
vectors to
Cincinnati. Due to the lose of electrical power, 797's
transponder was
not functioning so the controllers had no indication of the aircraft on
radar. Smoke had now filled the cabin, passengers being supplied with wet
towels to hold over their face, and into the flight deck, the door having
been left open.

Burned Fuselage of 797

Both pilots donned their oxygen masks and Cameron put on goggles. Once 797
got closer to Cincinnati, the
Approach
controller was able to pick up the aircraft's target on radar. Because only
emergency power was available, the pilots only had a back-up
attitude
indicator available to them. 797 was now 21 miles southeast of the
airport descending through 8,000ft in solid cloud. The
approach
controller instructed 797 that it would receive a
no gyro approach
to runway 27L. 797 descended to 2,500ft and was able to get into clear
conditions, though visibility was by no means good in the cockpit. Ouimet
periodically opened his sliding window to vent smoke out. As the controller
turned 797 onto final, he turned the runway lights up full. Ouimet exclaimed
"OK...we have the airport!" to which
approach
replied "The tower has you in sight and you are cleared to land." Ouimet
yelled back into the cabin for everyone to sit down and a few moments later
797 touched down smoothly. Because the electrical power had been lost, brake
antiskid was inoperative and four main tires blew out. After stopping and
shutting down, Ouimet immediately exited through his sliding window and
assisted the Cameron out from his side. Almost all of the emergency doors
were opened immediately and passengers began evacuating. Unfortunately, the
smoke was so thick that some passengers could not find their way to the
exits before flames engulfed the aircraft. 23 people were killed in the
fire. ......Investigation of the toilet flush motor
showed that it had not failed prior to the incident nor had it been damaged

internally by heat. Tests showed that, even if it had overheated, the
magnitude of the heat would not be sufficient to ignite adjacent materials.
Analysis of the motor wiring showed that it had been damaged by an already
existing fire which caused the circuit breakers to trip. Study of the
aircraft showed that the fire had begun behind the toilet's back wall,
burning through the walls and allowing smoke to enter the toilet. This was
the reason no fire was seen when the flight attendant emptied the fire
extinguisher in the toilet. As the fire burned down below the toilet, the
heat was blow onto the generator cables and the circuits opened, taking them
offline. The fire then continued to burn in the space between the toilet
wall and the aircraft's outer skin, allowing the fire to move forward above
the ceiling panels and enter through the ceiling and sidewall panels.
Unfortunately, as soon as the aircraft stopped and the doors were opened,
fresh oxygen was available to feed the fire and the aircraft was quickly
consumed. The precise origin of the fire has never been determined.

Remarks:
At 16.25h CDT Flight 797 took off from Dallas for a flight to
Montreal via Toronto. At 18.51h EDT, while cruising at FL330, the
three aft lavatory flush motor circuit breakers tripped. The
captain thought the plush motor had probably seized and waited for
about eight minutes before (unsuccessfully) trying to reset them.
At about the same time a strange odor was smelled at the aft of
the plane. After finding out that the lavatory was full of smoke,
a cabin attendant used the CO2 bottle to put out the fire (though
only black smoke was seen coming out of the seams of the
lavatory's walls). The first officer went over to take a look, but
had to return to the cockpit to get his goggles. When returning to
the cockpit at 19.07h, the 1st officer told the captain he thought
it best to descend. Around that time the aircraft started
developing electrical problems and a Mayday call was issued.
Flight 797 stared to descend and contacted Cincinnati at 19.10h
for an emergency. During the descent smoke began to fill the
passenger cabin. The emergency landing was carried out on runway
27L at 19.20h. The Cincinnati fire services were not able to put
out the fire, which gutted the fuselage. PROBABLE CAUSE: "A fire
of undetermined origin, an underestimate of fire severity, and
conflicting fire progress information provided to the captain.
Contributing to the severity of the accident was the flight crew's
delayed decision to institute an emergency descent."
(NTSB/AAR-84/09)